Combined anchor and pump shoe



M. W. HAINES COMBINED ANCHOR AND PUMP SHOE May 21, 1968 2 Sheets-Sheet 1Filed March 16, 1966 Wffflf/d/Afl/A/ZS INVENTOR.

May 21, 1968 M. w. HAINES COMBINED ANCHOR AND PUMP SHOE 2 Sheets-Sheet 2Filed March 16, 1966 4 \WW MR W 1\\& 4 v 5 Wm M a w a 3 6 a W I ll m a aJ /w Z WM w i M Z 2% 4V a d Z a a Q, @XQ 0 United States Patent3,384,179 COMBINED ANCHOR AND PUMP SHOE Marcus W. Haines, Long Beach,Calif. (21902 Goshute Ave., Apple Valley, Calif. 92307) Filed Mar. 16,1966, Ser. No. 534,885

8 Claims. (Cl. 166212) The present invention relates to anchors for usein oil wells and more particularly to a combined anchor and pump shoeadapted for use in connection with holding or anchoring the wellproduction tubing within the well pipe or casing so as to preventworking of the tubing with the typical reciprocating pump employed tolift the production fluid through the tubing to the earths surface.

More recently it has become the practice to drill relatively smalldiameter well bores which are cased with small diameter well pipe-r orcasing and the production pipe or tubing employed to conduct the wellfluids to the surface is also of comparatively small diameter, posingproblems in respect of the conventional equipment to be employed in theproduction of the well, including the reciprocating or sucker rod pumpassemblies and devices for anchoring the tubing against working with thepump. Working of the tubing with the pump involves the cyclicalstretching and contraction of the tubing as the rod pump isreciprocated. In normal well applications it is the practice to installin the tubing an anchor which may either be mechanically orhydraulically actuated into anchoring enga'gement wit-h the well casingor liner so as to anchore the tubing against such Working.

An example of such a tubing anchor is shown in my prior Patent No.2,874,783, granted Feb. 24, 1959, wherein an hydraulically actuatedfriction anchor is illustrated as being installed in the productiontubing above a sucker rod pump.

With the advent of smaller diameter wells the maintenance of adequatepassageway through tubing anchors both of the kind disclosed in my abovementioned patent and in other kinds of hydraulic or mechanicallyactuate-d anchors whereby retrievable pump assemblies may-be run andretrieved has posed a problem which the present invention obviates.

An object of the present invention is to provide a combined tubinganchor and pump shoe assembly adapted to be employed in a well to holdthe tubing against working with the pump and wherein the anchor ishydraulically actuated so as to have an anchoring action which isproportional to the hydrostatic head acting thereon and wherein theanchor is so disposed relative to the pump shoe that t the typicalsucker rod pump assembly may be run and retrieved and engaged anddisengaged from the shoe without interference from the anchor, even inthe small diameter wells.

In accomplishing the foregoing, it is a further objective to provide aunitary and simple assembly comprising an elongated tubular anchor bodyhaving adjacent its upper end and interally thereof a typical API pumpshoe, and having within the body means which cooperate with the body todefine a first fluid passage adapted to establish communication betweenthe well below the anchor and the pump shoe and to define a second fluidpassage or chamber which communicates through the body with the tubingabove the shoe, the anchor body having fluid pressure operated anchormeans thereon adapted to be actuated into engagement with the wellcasing responsive to the pressure of fluid in the just mentioned secondfluid passage or chamber, this pressure being a function of thehydrostatic head of fluid in the tubing.

Other objects and advantages of the invention will he hereinafterdescribed or will become apparent to those "ice skilled in the art, andthe novel features of the invention will be defined in the appendedclaims.

In the accompanying drawings:

FIG. 1 is a view in longitudinal section illustrating the disposition ina well casing of a combined anchor and pump shoe made in accordance withthe invention, with a typical sucker rod pump seated in the shoe;

FIG. 2a is a view in vertical section and on an enlarged scale of theupper end assembly of the combined anchor and shoe shown in FIG. 1;

FIG. 2b is a downward continuation of FIG. 2a;

FIG. 3 is a transverse sectional view as taken on the line 3-3 of FIG.2b;

FIG. 4 is a transverse sectional view as taken on the line 44 of FIG.2a; and

FIG. 5 is a view corresponding to FIG. 2a, but illustrating a modifiedform of pump shoe.

Like reference characters in the several views of the drawings and inthe following description designate corresponding parts.

Referring first to FIG. 1, there is generally shown a representativeinstallation of a combined anchor and shoe made in accordance with theinvention in a well pipe or casing C which has been perforated as at 1to provide openings through which well fluids may flow from thesubsurface formation into the casing for subsequent production. It willbe understood that other known modes of producing the well may beavailed of, namely the fluids may flow into an open or uncased hole orthe production sands may be retained behind a liner or gravel pack, allas known in the art, and a perforated casing is merely exemplary. In theillustration the well fluids are to be produced by a pump P comprising atypical working barrel 2 having reciprocable therein a valve plunger 3.At the base of the barrel 2 is a typical standing valve assembly 4adapted to permit the entry of well fluids into the working barrel 2when the plunger 3 and its travelling valve are moved upwardly by astring of sucker rods R. At the upper end of the working barrel 2 aresuitable passages 5 through which produced fluid will pass into theproduction tubing generally denoted at T.

Connected to the tubing T is the anchor A of the combined anchor andshoe of the present invention and within the anchor A is the shoe S inwhich the pump P seats.

The shoe S may be of any desired type but, as illustrated, wouldpreferably be of a standard API type such as a bottom lock shoe havingat its upper extremity a tapered seat 6 in which the lower taperedextremity 7 of the pump standing valve engages, and also having aninternal shoulder 8 with which typical latching fingers below the pumpstanding valve will engage to latch the pump assembly P on the taperedseat 6 of the shoe. The pump latch assembly has flow passage 10 so thatwell fluids may pass through the standing valve assembly into the pumpbarrel 2.

Depending from the shoe S is an elongated tubular member 11 whichextends in the illustrative embodiment the full length of the anchor Aand is connected to the anchor body in such a manner as will hereinafterbe more particularly described as to provide between the shoe and itsdepending extension 11 a chamber 12 which opens at the upper end of theshoe into the tubing T so that the pressure of fluid in this chamber isa function of the hydrostatic column in the tubing. The depending member11 has a central passage 13 therethrough which at its lower endcommunicates with the open well pipe or casing C so as to receive wellproduction fluids passing into the casing through the perforations 1.

It will now be understood that well fluids are produced upwardly throughthe depending extension 11 through the bottom lock for the pump Pthrough the standing 3 valve by the travelling valve and plungerassembly in response to reciprocation of the rod string R. Carried bythe anchor A are anchor means generally denoted at which, as will behereinafter more fully described, are hydraulically actuated by thepressure of the column of fluid acting in the chamber 12.

Referring now to FIGS. 2a through 4, the details of construction of theillustrative embodiment of the combined anchor and shoe will be betterunderstood. It will be noted that the anchor A comprises an elongatedbody 16 having adjacent its upper end an enlarged body section 17provided with thread means 17' for connection to the tubing T.Internally of the enlarged body section 17 is a shoulder 18 which, asseen in FIG. 4, has suitabl provided thereon a suitable number ofspacers 19 adapted to be engaged by a tapered surface 20 at the bottomof the pump shoe S. In addition, suitable spacers 21 may be providedadjacent the upper end of the pump shoe so as to dispose the pump shoe Sconcentric within the body section 17 of the anchor, thereby assuringthe provision of an annular space therebetween.

Extended through the body 16 of the anchor is a bore 22 in which isdisposed the aforementioned depending extension 11 of the shoe S. Thisextension 11 passes through the lower end of the body 16 of the anchorand is provided with a threaded lower extremity 11a engageable by a nut11b and a jam nut 11c whereby to securely load the shoe S against thestops 19 described above and so as to positively secure the shoe and itsextension 11 within the anchor. Sealing means in the form of a sealingring 23 are provided, as for example between the nut 11b and the lowerend face of the anchor 16, so as to separate the chamber 12 within thebody 16 from the well bore outside of the anchor.

The anchor body 16 has a central section 24 of enlarged cross sectionalconfiguration provided with a suitable number of radially extended bores25 in each of which is disposed a piston 26. As best seen in FIG. 3, thepistons and bores 25 are preferably symmetrically arranged about theanchor so that in addition to providing the anchoring effect desired theassembly will also be substantially centralized within the casing C whenanchored in the latter.

In the illustrative embodiment of the anchor, longitudinally extendedfriction anchor members 27 extend longitudinally and in overlyingrelation to the outer ends of the pistons 26. At the upper extremitiesof the anchor members 27 each is provided with an inturned flange 27aadapted to engage in a groove 27b in the anchor body 16. A retainingcollar 28 suitably mounted upon the anchor body 16 by fastening means 29is provided with a skirt 30 which engages the ends of the anchor members27 retaining the same in place on the body 16. At the lower extremitiesof the anchor members 27, they are provided with inturned flanges 27awhich engage in an elongated groove 27d in the anchor body 16, theselower ends of the anchor members 27 being retained by a skirt 31provided on a collar 32 which is secured to the body 16 by fasteningmeans 33.

It will be noted that this construction of the anchor members 27 and themeans for attaching the same to the anchor body will allow for lateraldeformation of the anchor members 27 responsive to forces appliedoutwardly by the pistons 26. It will also be understood that the effectof pressure differential acting on the pistons 26 is a function of thedifference between the pressure of the fluid column in the tubing T andthe column of fluids within the casing C outside of the anchor.

Referring to FIG. 5, the upper end of a modified assembly is shown, thisassembly being identical to that previously described with the exceptionof the shoe S which, in the embodiment of FIG. 5, is provided with aconical seat 6' adjacent the lower end of the shoe, there being asubstantially cylindrical wall 8' above the conical seating wall 6adapted for sealing engagement with the sealing elements of a pumpassembly having an hydraulic bottom lock. Such a lock, as known in theart, is provided with swabs which cause the pump to be held against theseat by differential pressure. Such differential pressure would be thesame pressure which in the present invention actuates the anchor. Inaddition, in the embodiment of FIG. 5 it will be noted that means areprovided for separably connecting the shoe S to the downward extension11, such means comprising a threaded upper end on the extension 11engaged in complemental threads on the lower end of the shoe, all asindicated at S. With such a construction it will be understood thatvarious types of pump shoes may be employed in connection with theanchor A, as may be dictated :by the type of pump to be employed.

In use, the anchor and shoe assembly will be connected in a string ofwell tubing T and run into the well casing to the desired depth ascustomary. The lower end of the anchor assembly may be either connectedto a downward extension of the tubing or the well production fluids mayenter the lower end of the anchor assembly as specifically illustrated.

Thereafter, the pump assembly P will be run into the tubing on thesucker rod string until the working barrel and more particularly thelower extremity of the pump assembly lands upon the seat provided by thepump shoe. In the structure of FIG. 1, it will be noted that the pumpassembly will be positively latched in place upon landing in the shoebut will be retrievable upon pulling upwardly on the rod string adistance greater than its permissible travel within the working barrelof the pump. In the case of a shoe of the type shown in FIG. 5, the pumpwill land in the shoe but differential pressure will retain the pump inthe shoe after the pump commences to operate.

Upon operation of the pump each stroke of the pump will displace fluidfrom the pump barrel into the tubing above the pump barrel and suchfluid will fill the chamber between the pump shoe and the downwardextension 11 so as to act upon the inner ends of the pistons 26. As thecolumn of fluid in the tubing T increases in height, the differentialpressure acting across the pistons will correspondingly increase so asto force the friction anchor member 27 outwardly into engagement withthe well casing C. It will also be understood to be within the purviewof the invention that the outward extremities of the pistons themselvesmay provide the friction surfaces engageable with the casing, or indeed,the invention contemplates the use of more positive anchoring elementshaving typical wickered surfaces for biting into the well casing. It ispreferred, however, that friction anchor elements be employed so as toavail of the advantages ascribable thereto in terms of certainty ofrelease when it is desired to pull the anchor assembly from the wellbore, as well as in terms of provision of predictable holding oranchoring effort based on the area of frictional contact and a knownanchoring pressure.

While specific structural details have been shown and described, itshould be understood that changes and alterations may be resorted towithout departing from the spirit of the invention as defined in theappended claims.

I claim:

1. A combined anchor and pump shoe for use in a well to anchor welltubing against working with a pump relative to the well casing,comprising: a tubular anchor body adapted to be connected in the welltubing; a pump shoe connected to said body; means defining a productionfluid passage through said body to said pump shoe and a chamber in saidbody separated from said passage and opening between said body and saidshoe for communication with the well tubing above said shoe; and anchormeans carried by said body and operable responsive to fluid pressure insaid chamber to be forced outwardly into anchoring engagement with thewell casing.

2. A combined anchor and pump shoe as defined in claim 1, wherein saidanchor means comprises a plurality of circumferentially spaced pistons;and radial bores in said body in which said pistons are reciprocable;said bores communicating with said chamber.

3. A combined anchor and pump shoe as defined in claim 1, wherein saidanchor means comprises a plurality of circnmferentially spaced pistons;radial bores in said body in which said pistons are reciprocable; saidbore communicating with said chamber; and friction anchor means movableby said pistons for frictional engagement with said well case.

4. A combined anchor and pump shoe as defined in claim 1, wherein saidmeans defining said production fluid passage comprises a tubular memberdepending from said shoe and connected to said anchor body below saidanchor means; and means providing a seal between said extension and saidanchor body.

5. A combined anchor and pump shoe as defined in claim 4, wherein meansare provided for separably connecting said shoe to said downwardextension.

6. Apparatus as defined in claim 1, wherein said anchor body is providedwith a seat for said shoe and including means concentrically disposingsaid shoe in said seat and providing for the passage of fluidtherebetween; and said means defining a production fluid passage throughsaid body including a downward extension on said shoe; and means forconnecting said downward extension to said anchor body and holding saidshoe on said seat.

7. A combined anchor and pump shoe for use in a well to anchor welltubing against working with a pump relative to the well casing,comprising: a tubular anchor body adapted to be connected in the welltubing; said body having an opening therethrough; means defining a seatfor a pump shoe in the upper end of said body; a pump shoe disposed onsaid seat; a downward extension depending from said shoe; means at thelower end of said extension for connecting said extension to said body;means defining a seal between the lower end of said extension and saidbody; said body between said shoe and the lower end of said extensionhaving a chamber opening between said body and said shoe forcommunication with the well tubing; and fluid pressure operated pistonmeans carried by said body and exposed to said chamber and operable toeffect anchoring of said anchor body in the well casing.

8. A combined anchor and pump shoe for use in a well to anchor Welltubing against working with a pump relative to the well casing,comprising: a tubular anchor body adapted to be connected in the welltubing; said body having an opening therethrough; means defining a seatfor a pump shoe in the upper end of said body; a pump shoe disposed onsaid seat; a downward extension expending from said shoe and opening atits lower end for communication with the well below said shoe; meansconnecting said shoe to the body; and anchor means carried by said bodyand actuatable outwardly for anchoring engagement with said well casing.

References Cited UNITED STATES PATENTS 2,074,912 3/1937 Hutto 103-219 X2,298,567 10/1942 Kelly et al 103219 X 32,552,153 5/1951 Crake 166-212 X2,874,783 2/1959 Haines 166-212 JAMES A. LEPPINK, Primary Examiner.

1. A COMBINED ANCHOR AND PUMP SHOE FOR USE IN A WELL TO ANCHOR WELLTUBING AGAINST WORKING A PUMP RELATIVE TO THE WELL CASING, COMPRISING; ATUBULAR ANCHOR BODY ADAPTED TO BE CONNECTED IN THE WELL TUBING; A PUMPSHOE CONNECTED TO SAID BODY; MEANS DEFINING A PRODUCTION FLUID PASSAGETHROUGH SAID BODY TO SAID PUMP SHOE AND A CHAMBER IN SAID BODY SEPARATEDFROM SAID PASSAGE AND OPENING BETWEEN SAID BODY AND SAID SHOE FORCOMMUNICATION WITH THE WELL TUBING ABOVE SAID SHOE; AND ANCHOR MEANSCARRIED BY SAID BODY AND OPERABLE RESPONSIVE TO FLUID PRESSURE IN SAIDCHAMBER TO BE FORCED OUTWARDLY INTO ANCHORING ENGAGEMENT WITH THE WELLCASING.